IP66 vs IP27
Head-to-head comparison of two IEC 60529 ingress protection ratings.
IP66 and IP27 are both IEC 60529 ingress protection codes, but they differ in solid-object protection (level 6 vs 2) and liquid protection (level 6 vs 7). IP66 is rated for dust-tight and powerful water jets (12.5 mm nozzle), while IP27 provides > 12.5 mm — finger and temporary immersion (up to 1 m).
IP66 is dust-tight and resists powerful water jets (12.5 mm nozzle, 100 kPa). A robust outdoor rating for equipment exposed to heavy rain, storms, or directed high-pressure hosing (but not high-pressure washdown).
The IP27 classification guarantees protection against solid objects larger than 12.5 mm and protection against the effects of temporary immersion in water. Ingress of water in quantities causing harmful effects shall not be possible.. It is an IEC 60529 ingress protection code combining first-digit (solid) level 2 with second-digit (liquid) level 7.
Detailed comparison
The stronger rating on each row is highlighted in emerald.
Solid protection (first digit)
IP66
6 — Dust-Tight
IP27
2 — > 12.5 mm — Finger
Liquid protection (second digit)
IP66
6 — Powerful Water Jets (12.5 mm nozzle)
IP27
7 — Temporary Immersion (up to 1 m)
Dust-tight
IP66
Yes
IP27
No
Water-jet resistant
IP66
Yes
IP27
Yes
Submersible
IP66
No
IP27
Yes
Outdoor suitable
IP66
Yes
IP27
Yes
The exact difference (IP66 vs IP27)
Solid protection
IP66
Level 6 — Dust-Tight
IP27
Level 2 — > 12.5 mm — Finger
IP66 provides "Dust-Tight" (level 6), while IP27 provides "> 12.5 mm — Finger" (level 2). IP66 is 4 levels higher.
Liquid protection
IP66
Level 6 — Powerful Water Jets (12.5 mm nozzle)
IP27
Level 7 — Temporary Immersion (up to 1 m)
IP66 handles 100 kPa (Powerful Water Jets (12.5 mm nozzle)), while IP27 handles Hydrostatic ~10 kPa at 1 m (Temporary Immersion (up to 1 m)). IP27 provides 1 level more liquid protection.
NEMA equivalents
No direct NEMA equivalent.
Recommendation
IP66 offers higher overall protection than IP27. Choose IP66 for harsher environments; IP27 may suffice for milder conditions and can be more cost-effective.